I don't know how much time throw protection lasts since I can't think of an easy way to test it, but I've had this problem consistingly with F-Kouma's 214C too, and even 214A. I'm under the impression that it's something around 6 frames, which is enough to get mashed out of. Justice would've had it so that if someone pressed a button the protection would go away, but that does not seem the case.